8 void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
14 float hp = (h * 180.0 / M_PI) / 60.0;
15 float x = c * (1 - fabs(fmod(hp, 2.0f) - 1.0f));
17 if (hp >= 0 && hp < 1) {
21 } else if (hp >= 1 && hp < 2) {
25 } else if (hp >= 2 && hp < 3) {
29 } else if (hp >= 3 && hp < 4) {
33 } else if (hp >= 4 && hp < 5) {
49 void hsv2rgb_normalized(float h, float s, float v, float *r, float *g, float *b)
51 float ref_r, ref_g, ref_b;
52 hsv2rgb(h, s, v, r, g, b);
53 hsv2rgb(h, 0.0f, v, &ref_r, &ref_g, &ref_b);
54 float lum = 0.2126 * *r + 0.7152 * *g + 0.0722 * *b;
55 float ref_lum = 0.2126 * ref_r + 0.7152 * ref_g + 0.0722 * ref_b;
57 float fac = ref_lum / lum;
64 std::string read_file(const std::string &filename)
66 static char buf[131072];
67 FILE *fp = fopen(filename.c_str(), "r");
69 perror(filename.c_str());
73 int len = fread(buf, 1, sizeof(buf), fp);
76 return std::string(buf, len);
79 GLuint compile_shader(const std::string &shader_src, GLenum type)
81 GLuint obj = glCreateShader(type);
82 const GLchar* source[] = { shader_src.data() };
83 const GLint length[] = { (GLint)shader_src.size() };
84 glShaderSource(obj, 1, source, length);
87 GLchar info_log[4096];
88 GLsizei log_length = sizeof(info_log) - 1;
89 glGetShaderInfoLog(obj, log_length, &log_length, info_log);
90 info_log[log_length] = 0;
91 printf("shader compile log: %s\n", info_log);
94 glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
95 if (status == GL_FALSE) {
102 void multiply_3x3_matrices(const Matrix3x3 a, const Matrix3x3 b, Matrix3x3 result)
104 result[0] = a[0] * b[0] + a[3] * b[1] + a[6] * b[2];
105 result[1] = a[1] * b[0] + a[4] * b[1] + a[7] * b[2];
106 result[2] = a[2] * b[0] + a[5] * b[1] + a[8] * b[2];
108 result[3] = a[0] * b[3] + a[3] * b[4] + a[6] * b[5];
109 result[4] = a[1] * b[3] + a[4] * b[4] + a[7] * b[5];
110 result[5] = a[2] * b[3] + a[5] * b[4] + a[8] * b[5];
112 result[6] = a[0] * b[6] + a[3] * b[7] + a[6] * b[8];
113 result[7] = a[1] * b[6] + a[4] * b[7] + a[7] * b[8];
114 result[8] = a[2] * b[6] + a[5] * b[7] + a[8] * b[8];
117 void multiply_3x3_matrix_float3(const Matrix3x3 M, float x0, float x1, float x2, float *y0, float *y1, float *y2)
119 *y0 = M[0] * x0 + M[3] * x1 + M[6] * x2;
120 *y1 = M[1] * x0 + M[4] * x1 + M[7] * x2;
121 *y2 = M[2] * x0 + M[5] * x1 + M[8] * x2;
124 void invert_3x3_matrix(const Matrix3x3 m, Matrix3x3 result)
126 double inv_det = 1.0 / (
127 m[6] * m[1] * m[5] - m[6] * m[2] * m[4] -
128 m[3] * m[1] * m[8] + m[3] * m[2] * m[7] +
129 m[0] * m[4] * m[8] - m[0] * m[5] * m[7]);
131 result[0] = inv_det * (m[4] * m[8] - m[5] * m[7]);
132 result[1] = inv_det * (m[2] * m[7] - m[1] * m[8]);
133 result[2] = inv_det * (m[1] * m[5] - m[2] * m[4]);
135 result[3] = inv_det * (m[6] * m[5] - m[3] * m[8]);
136 result[4] = inv_det * (m[0] * m[8] - m[6] * m[2]);
137 result[5] = inv_det * (m[3] * m[2] - m[0] * m[5]);
139 result[6] = inv_det * (m[3] * m[7] - m[6] * m[4]);
140 result[7] = inv_det * (m[6] * m[1] - m[0] * m[7]);
141 result[8] = inv_det * (m[0] * m[4] - m[3] * m[1]);
144 void print_3x3_matrix(const Matrix3x3 m)
146 printf("%6.4f %6.4f %6.4f\n", m[0], m[3], m[6]);
147 printf("%6.4f %6.4f %6.4f\n", m[1], m[4], m[7]);
148 printf("%6.4f %6.4f %6.4f\n", m[2], m[5], m[8]);